PBS's Downton Abbey began its dramatic fourth season in the United States this month. The series has already been renewed for season 5, but will its fifth season be its last?

Julian Fellowes, Downton Abbey creator and writer, said is he not sure about the future of his hit series.

"I don't know yet if there is a season 6, but it's not going to go on forever," he said in an interview with Wall Street Journal. "It won't be 'Perry Mason.'"

It may appear that Fellowes is being vague, but it is possible that the creator is truly unsure of whether or not season 6 will happen. According to Gareth Neame, Downton Abbey executive producer, ITV, the channel that originally airs the show in Britain, orders episodes of the show one season at a time.

"ITV commission each series on a year-by-year basis," Neame said in a statement. "In an interview given to The Wall Street Journal(published December 31, 2013), Julian Fellowes stated that the show would not go on forever (inevitable of course and something both he and I have been on the record for previously). For now ITV have commissioned series five and that is what we are busy preparing."

Viewers can choose to look at the glass half-full, however, because Neame did not exactly say that the show would end before season 6.

"I can confirm that there are no plans to end the show after the fifth series," his statement said.

On the other hand, the glass could be considered half-empty. Back in 2012, Neame said that the show would most likely end after season 6, at the latest.

"We have to balance between continuing to make it for audiences around the world that adore it and making sure that we don't take it too far ... which is not now and not next year, but likely five years or six years, not 10 years," the producer said in an interview with The Hollywood Reporter.